Nimzo-Indian Defense: Hübner, Rubinstein Variation

1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 c5 5.Ne2 d5 6.a3 Bxc3+ 7.Nxc3 cxd4 8.exd4 dxc4 9.Bxc4 Nc6